A3 misfire?....

[catso]

My A3, (3.2 V6) has suddenly developed a misfire; it sounds/feels like one (or more) cylinder is missing but only does it under load and sounds/feels fine if revved in neutral or driving at constant speed, also whilst doing it the yellow 'engine' light flashes but goes off again when driving at a constant speed or in neutral.

Any ideas what to check, coil pack? spark plug?

TIA

[hman]

coil pack.

[catso]

Suspected that as I've heard it mentioned many a time on Audi forums.

Is it easy to change/find out which one?

[Doovde]

I'd get it checked out locally by someone with VAG-COM to see what the ECU is storing as faults. This will help you pin down whether it's individual coil packs or one of the power amplifiers (which drives the coil packs)

Edited by Doovde on Tuesday 26th May 15:35

[anonymous-user]

You don't need a VAG-COM to check coil packs or ignition modules (sometimes referred to as amplifiers). This is my tried and tested method from many years of 1.8T ownership.

To see if you have a coil pack problem simply remove the lead from one coil at a time and test the engine. If it gets worse then that coil is probably OK. If there's no change then that coil is probably knackered.

To check it's not a ignition module problem simply move the coil pack you have identified as possibly knackered and repeat the removing a lead test. If the problem moves with the coil then the coil is knackered. If the problem stays on the cylinder you moved the possibly knackered coil from then the problem is up the line maybe in the ignition module.

Mike

[Doovde]

Yeah, I suppose you could, and its good old fashioned process of elimination diagnosis, but it's gonna run like a dog with 2 of the 6 cylinders out, if you don't choose the right coil pack a few times.

A diagnostic tool will tell you which cylinder(s) are misfiring and lead you straight to the culprit (hopefully)

[catso]

Been to the dealers and there is bad news, apparently it's not a coilpack but a stretched camchain/failed chain tensioner meaning the cam timing is out (there was a post about this a couple of months back) and it is a big job - 14hrs labour?

Dealer initially quoted me almost £1500 but have, after some discussion re the low mileage and that I bought the car new and have had all the servicing done there, agreed to do it on an 80/20 'goodwill' basis which means it'll cost me just under £300.

I'm getting the, almost due service done at the same time so they've quoted me £400 all in, so not as bad as it could have been but still an unexpected hit after the £500+ it cost me last week for the fans & radiator.

Until now it has been a cheap(ish) car to run, other than petrol.

[phumy]

catso said:

Been to the dealers and there is bad news, apparently it's not a coilpack but a stretched camchain/failed chain tensioner meaning the cam timing is out (there was a post about this a couple of months back) and it is a big job - 14hrs labour?

Dealer initially quoted me almost £1500 but have, after some discussion re the low mileage and that I bought the car new and have had all the servicing done there, agreed to do it on an 80/20 'goodwill' basis which means it'll cost me just under £300.

I'm getting the, almost due service done at the same time so they've quoted me £400 all in, so not as bad as it could have been but still an unexpected hit after the £500+ it cost me last week for the fans & radiator.

Until now it has been a cheap(ish) car to run, other than petrol.

If your car has, as you say, "low mileage" why has the chain strectched?

What is your mileage?

If they are willing to go 80/20, i would push for 100% especially if youve had the car from new and you have a full service history with them and it has got a timing chain problem at low mileage.

[catso]

phumy said:

If your car has, as you say, "low mileage" why has the chain strectched?

What is your mileage?

If they are willing to go 80/20, i would push for 100% especially if youve had the car from new and you have a full service history with them and it has got a timing chain problem at low mileage.

Mileage is 45k at 5 yrs old, which is low considering warranty was 3 yrs/60k.

I don't know why it happened but I have heard about it before (on here) so I think it is a known issue on this engine? It happened suddenly as it was running fine & suddenly went to rough running which is why I thought it was electrical.

I agree it should be free & I tried to get more but 80/20 was as far as I could get them to go, maybe I should push the issue with Audi? but I had been quoted £360 for the service that was upcoming (in about 3k) so I suppose it's not too bad if I look at it that way (and probably cheaper than a coil pack?).